Yesterday we serviced my brother in law's Passat B6 2.0 TDI BKP.

 

We changed: oil, oil filter, air filter, fuel filter. Nothing unusual, and I've done it many times before on my Fabia.

 

Went to start after putting it all back together, primed a few times to pull the fuel through the filter. First time, it started fine, but the engine was idling very rough.

 

Turned off to check that everything was back on properly, all appeared fine, next time, it just turns over and will not catch.

It doesn't sound like its struggling to turn over.

 

Disconnected all of the air intake to see if that's blocked, turns over but will not catch.

 

I pulled the top of the fuel filter out to see if any fuel was being pumped, and nothing was coming through.

He informed me that it was on red, and had about 40 miles left on the trip computer. 

 

I went and got a 5L can of diesel just incase. That registered, fuel light went off, but still nothing.

 

Removed the back seat to look at the fuel pump on the tank, and it's not even making a sound. Checked that voltage is going to it when cranking, and it's receiving 12v. 

Pulled off the fuel line and connected a bit of temp hose to see if it was pumping anything, and nothing was coming out.

 

It looked like something had been spilt on the seat by a previous owner, as the top of the cover, inside the lid and sat on top of the pump was some sort of sticky yellow liquid. 

 

Was it just a really bad coincidence that it stopped working just at that point, or could trying to prime the new fuel filter with hardly any fuel in the tank have killed it?

Well it was confirmed as fuel pump failure.

 

Reading Passat forums a few have had fuel pump failures on similar age cars, some at 70mph!

 

I can only conclude that it was on its way out, and the extra strain from trying to prime the fuel system after the filter was changed was just enough to tip it over the edge.